1. Field of the Invention
This invention relates to packaging. More specifically, the invention relates to a multi-sided container or box made of corrugated paperboard. In particular, the invention relates to a corrugated paperboard tray for containing poultry products, wherein the tray has improved stacking strength and resistance to distortion from lateral forces applied to the sides or ends of the tray.
2. Prior Art
Various styles of paperboard boxes are known in the prior art for containing a variety of products. Conventional boxes may have four sides and be square or rectangular in plan view, or they may have eight sides, with opposed pairs of parallel side and end walls and diagonal corner panels oriented at 45° to the longitudinal axis of the box and connecting adjacent side and end walls.
Examples of prior art eight sides boxes or trays are disclosed in applicant's prior patents Des.361,892 and 5,752,648. These boxes are designed for containing poultry pieces packed in ice, and are usually termed poultry trays. They are formed from a unitary blank of corrugated paperboard, and are sometimes coated on both sides with wax or other material to impart rigidity and resistance to water degradation. The diagonal corner panels subtend an angle of 45° with respect to the longitudinal axis of the box.
Eight sided trays have greater compressive strength when stacked on top of one another, and exhibit less side wall bulge from the weight of the contents therein, than do four sided trays. However, because of the diagonally oriented corner panels, an eight sided tray tends to flex or distort, especially at the open top edge, when lateral force is applied to the sides or ends of the tray, as occurs for example when two eight sided trays are pushed together end-to-end during stretch wrapping of the trays to form a unit load. This distortion of the tray can result in dislodgement of the cover which is usually applied to the tray, or make it difficult to apply a cover. Additionally, these changes in dimension of the tray may cause other difficulties when the trays are palletized during shipment and/or storage. Additionally, there are no square corners on an eight sided tray around which a label can be wrapped so that it is visible from each of two adjacent sides.
Accordingly, there is need for a tray that has superior stacking strength and resistance to distortion when transverse forces are applied to the ends or sides of the tray.